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VINGENS J. M. GOTTLIEB, OF VEST HOBOKEN, NEXV JERSEY.

METHOD OF REPRODUCING DRAWINGSAND OTHER LINE WORKS OF ART.

SPECIFICATION forming part of Letters Patent No. 306,481, dated October14:, 1884.

Application filed February 7, 1884. (X0 specimens.)

To all whom it may concern.-

Be it known that I, VrNonNs Jaoon Macros GoTrLIEc, of West I-Ioboken, inthe countyof Hudson and State of New Jersey, have i11- vented anImprovement in the Method of Reproducing Drawings and Other Line \Vorksof Art, of which the following is a specification.

I am aware that drawings and other works of art in lines have beenreproduced by placing the same in contact with sensitized paper andexposing the same to sunlight, and then developing the copy; but inthese operations two difficulties arise: the first is that the lines areleft white and the background rendered blue or dark brown, and henceobjectionable in appearance and difficult to work from, especially inmachine drawings; the second is that nothing but at-ransparent or nearlytrans parent original on traeing-cloth or similar material can beemployed to print from, and the development is diiiicult, requiringspecial apparatus.

My invention is for simplifying the process and for rendering the linesblack, or nearlyso, while the background is of a light color, and is notliable to become dark by exposure to the light.

The following solution is made use of in preparing the paper, thematerials employed being those named, or substances having equiv-- alentchemical properties, and in about the proportions stated bichromate ofpotash, 9.6 grams; vanadate of ammonia, 0.015 grams; chloride of sodium,9.6 grams; sulphuric acid,

(about 98,) 21 grams; distilled water, 441

grams. These substances are to be carefully and thoroughly mixedtogether. The paper to be sensitized is coated over with this solution,and then allowed to dry for a few minutes in a dark place. Thereproduction is effected by exposure to the sunlight. With this objectin view, a tracing may be employed, or the drawing or other work of art.If the original is 011 tracing paper or cloth, or sufficientlytransparent, the reproduction may be effected by placing the linedsurface next to the glass and the sensitized paper beneath, and pressingthe two together from the back, as usual. If the drawing is ontranslucent paper, it may be placed with the lined surface directly uponthe sensitized paper. The reproduction in this case will be reversed. Aiter exposure for the proper length of time to the action of light,varying from ten seconds to fifteen minutes, according to the intensityof the light and the transparency of the original drawing, theimpression is removed and developed by steam and anilineoil. To effectthis a few drops of aniline-oil are put into the water, or the steamallowed to pass through a cloth upon which the oil is placed. Theexposure to the steam and vapor of the anilineoil may be in a closedvessel or box, or the paper may be passed over the vapors by hand in theopen atmosphere, after which the reproduction is dried quickly and willbe found to be a durable picture, the lines being black, or nearly so,and the surface or background of a very light greenish tinge.

I have sometimes added ether or aqua-aid monia to the solution beforenamed for varying the color of the lines or the background,

or for rendering the surface more or less sensitive than that preparedby the aforesaid formula. The ammonia renders the operation morereliable, so that the lines are not injured if the exposure isunnecessarily long.

I claim as my invention The method herein specified of copying drawingsand works of art in lines, consisting in covering a sheet of paper witha solution of bichromate of potash, vanadate of ammonia, chloride ofsodium, sulphuric acid, and water, exposing the sheet to the actionoflight while in contact with the article to be copied, and developingand fixing the print by steam and aniline-oil, substantially as setforth.

Signed by me this 4th day of February, A. D. 188%.

V. J. M. GOTTLIEB. lVitnesses:

G150. T. PINOKNEY, VILLIAM G. ll'lo'r'r.

